chapter 13

Question 1

All populations experience fluctuations due to

Answer 1

availability of resources, predation, competition, disease, parasites, and climate.

Question 2

what allows larger organisms to maintain homeostasis in the face of unfavorable environmental changes.

Answer 2

Larger organisms have a lower surface-area-to-volume ratio

Question 3

What can the age structure of a population tell us about pop. fluctuations over time?

Answer 3

It can show times of particular growth or decline in previous years.

Question 4

When an age group contains a high or low number of individuals, the population likely experienced

Answer 4

high birth or death rates in the past.

Question 5

when a population grows beyond its carrying capacity; often occurs when the carrying capacity of a habitat decreases from one year to next (e.g., because less resources are produced).

Answer 5

Overshoot

Question 6

a substantial decline in density that typically goes well below the carrying capacity.

Answer 6

Die-off

Question 7

regular oscillation of a population over a longer period of time.

Answer 7

Population cycles

Question 8

Cyclic populations can occur among

Answer 8

related species and across large geographic areas

Question 9

Populations are stable at their

Answer 9

carrying capacity

Question 10

Why are some pops. inherently cyclical?

Answer 10

There is a delay between the time of breeding and the birth of offspring.

Question 11

when density dependence occurs based on a population density at some time in the past.

Answer 11

Delayed density dependence

Question 12

r =

Answer 12

intrinsic growth rate

Question 13

N =

Answer 13

current population size at time t

Question 14

K =

Answer 14

carrying capacity

Question 15

dn
____=
dt

Answer 15

rate of change in population size

Question 16

How can energy reserves make a pop. experience delayed density dependence?

Answer 16

They enable the population to survive above carrying capacity.

Question 17

Delayed density dependence may occur because the

Answer 17

organism can store energy and nutrient reserves.

Question 18

When populations are low and food is abundant, the water flea Daphnia galeata stores surplus energy as lipid droplets.
is an example of

Answer 18

Delayed density dependence

Question 19

Delayed density dependence can occur when there is a

Answer 19

time delay in development from one life stage to another.

Question 20

Small populations are more vulnerable to extinction

Answer 20

than larger populations.

Question 21

Which is an example of demographic stochasticity?

Answer 21

low fertility for some individuals

Question 22

variation in birth rates and death rates due to random differences among individuals

Answer 22

Demographic stochasticity

Question 23

variation in birth rates and death rates due to random changes in the environmental conditions

Answer 23

Environmental stochasticity

Question 24

the process of breaking up large habitats into a number of smaller habitats.

Answer 24

Habitat fragmentation

Question 25

high-quality patches that produce a large number of individuals that disperse to other patches

Answer 25

Sources

Question 26

low-quality patches that produce few individuals and rely on dispersers to keep the sink population from going extinct.

Answer 26

Sinks

Question 27

We can increase the number of occupied habitat patches by providing

Answer 27

corridors between patches to increase the rate of colonization (c).

Question 28

We can also increase the number of occupied patches by

Answer 28

decreasing rates of extinction (e).

Question 29

Dispersal success is inversely related to

Answer 29

the distance of dispersal;

Question 30

refers to the dispersal between source and sink populations.

Answer 30

) The rescue effect

Question 31

when dispersers supplement a declining subpopulation and thereby prevent it from going extinct.

Answer 31

Rescue effect